Replies to This Discussion

Permalink Reply by Chris Anderson on January 2, 2010 at 7:45pm

Yes, that's usually fine. All they need is a temp difference between ground and sky. Nightime, winter, doesn't matter.

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Permalink Reply by Krzysztof Bosak on January 3, 2010 at 4:39pm

But the snow does...
Chris, the snow matters.
It is sticky and covers any of the thermopiles it hits.
A single hit and it is a few to 45 degrees off.
Same as rain.
Some thermopile autopilot manuals even warn against the rain,
but the maker hasn't seen the snowfall at his location, what is normal.

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Permalink Reply by Nicholas Budd on January 3, 2010 at 5:02pm

He asked about snow on the ground and blue sky. I assume that means not during the actual snowfall, which means it should be fine.

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Permalink Reply by olli on January 3, 2010 at 9:52pm

yes i now.snowFALL and rain make issues......


i mean not snowFALL i mean a sunny day.goot waether.but ON GROUND 30cm snow .....

then is the ground cold also....

olli

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Permalink Reply by Nicholas Budd on January 4, 2010 at 3:08am

The sky reads as something like -40 celsuis in IR, so unless you're flying in the antarctic, it's unlikely that a little snow on the ground will confuse the thermopiles. Even with snow, the earth radiates heat from the sun that the thermopiles can 'see'.

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Permalink Reply by olli on January 4, 2010 at 5:12am

ok, i understand....


thanks for info



olli

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